Final answer:
The product of force and the time interval it acts over is called impulse, which relates to the change in momentum of a system in physics. For non-constant forces, an average effective force is used to compute the impulse equivalent to the varying force.
Step-by-step explanation:
The product of the force acting on a system and the time interval during which the force acts is known as impulse. In physics, impulse is important because it is related to the change in momentum of a system. The equation representing impulse (J) can be written as J = F ∙ Δt, where F is the average force applied and Δt is the time interval over which the force is applied. If the force is not constant over the time interval, an average effective force Feff can be calculated that produces the same change in momentum as the varying force would.
Furthermore, it's important to note that the concept of work, which is the product of force and the distance over which it acts, is distinct from impulse. While work relates to the force causing displacement, impulse relates to the force causing a change in momentum. Impulse has significant applications in various scenarios such as objects colliding or changes in velocity of moving objects.